半横向排烟下隧道火灾烟气控制效果试验研究

为了研究隧道火灾半横向排烟对烟气排放效果的影响参数,同时为半横向通风排烟下隧道火灾烟气蔓延情况的系统性研究提供试验数据支持,建立缩尺比例为1：10的水平模型隧道开展火灾试验,并对火灾半横向排烟时排烟阀和排烟道内的烟气流动进行理论分析。结果表明,水平公路隧道半横向排烟情况下,理论分析得出的排烟阀处烟气流速与模型试验结果基本吻合;在火源附近,冷空气与高温烟气掺混较少,温度较高;在靠近风机处,排烟阀烟气流速较大,但同时因远离火源,热量损失和掺混冷空气较多,因而温度较低;排烟阀开启个数、间距、单个面积以及排烟阀离风机的距离,均会对半横向排烟系统的排烟效果产生影响。

Experimental Study on Effect of Semi-horizontal Extraction on Tunnel Fire

The paper is aimed to study the factors affecting the smoke movement,and obtain the experimental data on the smoke spread in the semi-horizontal extraction system in tunnel fires.A series of tests are conducted in a model tunnel of ratio 1：10,and the theoretical analysis of smoke flow at the exhaust in-lets and duct is performed.The results indicate that the theoretical analysis is basically consistent with the model test data.Smoke is hot at the near field of the fire since little cold air is drawn to the fire and the mixing of smoke and air is not strong.However,the smoke temperature near the exhaust inlets far away from the fire is low,because of the heat loss to the boundaries and more mixing with cold air.Performance of the extraction of semi-horizontal system in tunnel fire is dependent on number,spacing,area of exhaust inlets and distance from the fan.